The pyramids in Giza were being built while there were still mammoths on the planet
Scientists claim that all the pyramids were built between the 26th century and the 23rd century BC. Mammoths appeared around 1.6 million years ago and went completely extinct only in the 10th century BC. This means that while Cheops was happy about a new pyramid that was being named after him, somewhere thousands of miles away huge animals were scaring our ancestors.
Source: Bright Side: https://brightside.me/wonder-curiosities/14-startling-facts-that-impressed-us-664810/